1. Field of the Invention
The present invention is directed to an x-ray diagnostics installation, and in particular to such a diagnostics installation having an x-ray source, an x-ray image intensifier connected to a video chain, a processing circuit which controls certain of the installation components, and a monitor on which the image is displayed.
2. Description of the Prior Art
German No. OS 32 25 061, corresponding to U.S. Pat. No. 4,517,594, discloses an x-ray diagnostics installation wherein a portion of the output image from the x-ray image intensifer is coupled by a light distributor onto a detector, which consists of a matrix of photosensors. The parallel outputs of the photosensors are connected to a summing amplifier is respective switches. The output signals from the individual photosensors are weighted by variable resistors.
A disadvantage of this installation is that a light distributor must be provided. Additionally, the structure of the matrix is relatively complicated, because each photosensor must have an amplifier connected thereto. Because the amplifiers occupy a portion of the total matrix area, space limitations impose a limit on the number of photosensors per unit area which can be used. Additionally, even though the weighting resistors can be varied, the resistors retain the set value until re-set, and thus it is not possible to undertake a continuous or dynamic modification and matching of the weighting.